Font size
Worksheets11 Evolution Of Populations
Total questions: 83
Worksheet time: 42mins
A measure of how commonly a particular allele occurs in a population
allele frequency.
gene pool.
mutation rate.
phenotype
The more genetic variation a population has, the more likely it is that some individuals will
survive
evolve
migrate
mutate
Genetic variation can arise from a random change in the DNA of a gene. This change is called a(n)
mutation
allele
gene pool
gene flow
The normal shuffling of alleles during meiosis results in
recombination
reproduction
hybridization
mutations
Which term means the crossing of two different species that share common genes?
hybridization
mutation
population
recombination
What is the observable change in the allele frequencies of a population over time called?
microevolution
selection
distribution
recombination
Natural selection that changes the distribution of a trait to favor one extreme phenotype is called
directional selection
disruptive selection
stabilizing selection
normalizing selection
In stabilizing selection, what occurs in a population?
The intermediate phenotype becomes more common.
The population shifts toward one of two extreme phenotypes.
Both extreme phenotypes shift toward the middle.
The intermediate phenotype becomes rare.
A population that is not undergoing natural selection displays what type of distribution?
normal
disruptive
directional
stabilizing
In a population of birds, intermediate beak size is selected against, and both very small and very large beak sizes are favored. What type of selection is this an example of?
disruptive
directional
normal
stabilizing
Chance changes in allele frequencies within a population are called
genetic drift.
gene flow.
gene pool.
sexual selection.
A small number of birds, blown off course during migration, find an island and colonize it. This population will most likely experience genetic drift as a result of the
founder effect.
bottleneck effect.
sexual selection.
mutations.
Fighting between male elephant seals over females is an example of
intrasexual selection.
bottleneck effect.
intersexual selection.
founder effect.
What increases genetic variation when animals move from one population to another population?
gene flow
bottleneck effect
sexual selection
genetic drift
A problem in all populations influenced by the bottleneck effect is that
genetic variation is lost.
alleles can’t become fixed.
offspring inherit harmful alleles.
chance no longer affects them.
Which of the following conditions could mean that a population is in Hardy-Weinberg equilibrium?
Mating is random.
The population is small.
Gene flow is common.
Mutations occur frequently.
The Hardy-Weinberg equation is used to
predict genotype frequencies in a population.
estimate the rate of mutations in a population.
determine the likelihood of random mating.
calculate the gene flow rate among organisms.
The five factors that can lead to evolution are gene flow, genetic drift, mutation, natural selection, and
sexual selection.
controlled mating.
emigration
immigration
Mutations are important because they bring about
genetic variation needed for a population to evolve.
death of the organism in which they develop.
benefits for the individual, but not for the population.
Hardy-Weinberg equilibrium within a population.
Which of the following statements applies to real populations?
Hardy-Weinberg equilibrium is rare.
Mutations are rarely passed to offspring.
Gene flow represses alleles for desirable traits.
Evolution cannot occur in large populations.
What is speciation?
divergence of two or more species from an existing one
timing of mating that prevents normal sexual selection
isolation that affects mating behavior
combining of two species to form one with different traits
A difference of chemical scents between two populations is an example of what kind of isolation?
behavioral
temporal
geographic
disruptive
An earthquake causes an ocean channel to open up on an island where a low area previously existed. The island’s lizard population is now separated on the two parts of the island, providing an example of
geographic isolation.
behavioral isolation.
disruptive selection.
temporal isolation.
Which of the following examples illustrates a temporal barrier to mating between populations?
Varieties of oak tree produce pollen during different seasons, so they can’t pollinate one another.
Populations of the same species of seal live on islands too far apart to swim between them for mating.
Species of birds have elaborate courtship dances, and females select the best dancers as mates.
Herds of caribou misinterpret each other’s mating behavior, so they fight instead of mating.
What kind of isolation occurs when two populations of birds have different courtship dances?
behavioral
temporal
sexual
geographic
Which of the following processes is considered to be random?
genetic mutation
natural selection
adaptive radiation
coevolution
The American flying squirrel and the flying phalanger of Australia live in similar environments and look very similar. However, they are not closely related. Their resemblance is most likely an example of
convergent evolution
temporal isolation
divergent evolution
sexual selection
The Galápagos Islands in the Pacific Ocean have varied habitats. Divergent evolution is occurring on these islands, meaning that the species that live there
had common ancestors but have become increasingly different
change in response to changes in other species they interact with
are becoming more like each other in response to their habitats
have lived unchanged through long periods of stability
Like all flowering plants, the snapdragon must be pollinated to reproduce, but its flowers are closed. A bumblebee has just enough weight to open a snapdragon flower by landing on it. This adaptation is an example of
coevolution
convergent evolution
divergent evolution
speciation
The total and permanent disappearance of a species from Earth is called
extinction
equilibrium
coevolution
radiation
Many years of evolution is most likely to produce
differences between species and their ancestors
species that are more likely to become extinct
species that are becoming more and more similar
decreasing numbers of species in each environment
What does the biodiversity on Earth indicate about its organisms?
They are adapted to live in a variety of environments.
They share many common structures and functions
They have not changed over the course of Earth’s history
They cannot tolerate extreme environments
An organism that inherits two alleles for a trait exhibits the trait if
one of the alleles is dominant
neither parent had the trait
all of its siblings have the trait
the environment favors the trait
In order for species to adapt and evolve, they must be able to
reproduce
fight off illness
interact randomly
establish habitats
Based on the evolution of the fictitious bird species shown in
Figure 11.1, which of the following statements is true?
A three-toed foot is likely an adaptation of the living species.
Toe count was not important in the species’ evolution.
A five-toed foot would likely be advantageous to the living species.
There must have been another intermediate species with a
four-toed foot.
We identify organisms as belonging to the same species if they are capable of
producing fertile offspring
inhabiting similar habitats
evolving comparable adaptations
having the same life expectancies
This map shows the seas that covered North America during part of the Cretaceous Period. What can you infer about the species that lived on the three separate landmasses?
Fewer species existed at that time.
All of them could survive underwater
They were adapted to different habitats
Many of them could swim
Sources of genetic variation include
social behaviors among animals
crossing over during meiosis
asexual reproduction by mitosis
environmental pressures on species
Which of the following is the best example of a population?
alligators of one species living in a certain swamp
all insect species living in the Amazon rain forest
all cat species living in North and South America
flowering plants and ferns growing in a garden
One theory explaining evolution is based on the mechanisms of
natural selection
homeostasis
sexual reproduction
species diversity
The combined alleles of
all the individuals in a population is called the
gene pool
phenotype
mutation rate
allele frequency
What are two main sources of genetic variation?
mutations and recombination
recombination and reproduction
recombination and extinction
mutations and extinction
Figure 11.1 shows how a population of cacti changes when it faces selective pressure from two predators: peccaries (wild pigs) and a parasitic insect. The dashed line shows the original population. The insects most often kill cacti with a(n)
high number of spines
intermediate number of spines.
low number of spines.
complete lack of spines.
What type of selection occurs when individuals in a population with the intermediate phenotype are selected for?
stabilizing selection
directional selection
intermediate selection
disruptive selection
Figure 11.2 shows the tail feather length of male widowbirds and their reproductive success. The males that had the greatest reproductive success were the birds with tails that were
relatively long
particularly short
mid-length
any length
When a few individuals start a new colony it most likely results in
genetic drift through the founder effect.
more variety in the new population.
extinction due to the bottleneck effect.
mutation due to disruptive selection.
The movement of alleles from one population to another is called
gene flow
founder effect
microevolution
genetic drift
A population that has a normal distribution of the range of heights has many individuals who are
average height and few who are very tall or very short.
short and few who are average or very tall.
tall and few who are average or very short.
average height and none who are very tall or very short.
What does being in Hardy-Weinberg equilibrium mean for a population?
The population is not evolving.
The population is evolving very rapidly.
Equilibrium would gradually end.
Gene flow would occur, but slowly.
If the actual allele frequencies in a population do not match genotype frequencies predicted by the Hardy-Weinberg equation, the population is
evolving
shrinking
isolated
extinct
Which of the five factors that can lead to evolution would operate on a change in body color that enabled animals to better hide from predators?
natural selection
genetic drift
sexual selection
gene flow
Reproductive isolation occurs when
members of different populations can no longer mate successfully.
the gene pools of different populations have become very diversified.
some catastrophic event greatly reduces the size of a population.
a small number of individuals moves and starts a new population.
What type of isolation occurs when the timing of reproduction is different between two populations?
temporal
geographic
behavioral
selective
Coevolution is a process in which species
evolve in response to changes in each other
become extinct and are lost permanently
become increasingly different from each other
evolve similar characteristics in different habitats
Two species that are closely related become increasingly different through
divergent evolution
disruptive selection
convergent isolation
competitive relationships
A population of squirrels that contains a wide range of phenotypes has a
large amount of genetic variation.
high allele frequency for most
poor chance of surviving habitat change.
decreased chance of frequent gene flow.
Mutations in the DNA of genes that can be passed onto offspring
result in increased genetic variation.
are more likely with genetic drift.
do not occur randomly during evolution.
are always harmful to the offspring.
Figure 11.1 shows the change in acactus population under pressure from peccaries (wild pigs) and parasitic insects. The dashed line shows the original cactus population. What type of selection does the graph show?
stabilizing
directional
intermediate
disruptive
In a population of foxes, tail length shows a normal distribution. On a graph, this frequency would produce what kind of curve?
bell-shaped
shifted right
doubled
tall and thin
Disruptive selection occurs when
selective pressures favor phenotypes that are
at both extremes.
close to the mean
toward one extreme
in a normal distribution
Figure 11.2 shows a graph of reproductive success versus tail feather length for male widowbirds. What type of selection is shown by these data?
sexual
disruptive
stabilizing
divergent
A tsunami has destroyed almost all of the palm trees in an area. This event will most likely lead to
genetic drift through the bottleneck effect.
gene flow following disruptive selection.
microevolution by reproductive isolation
speciation triggered by the founder effect
What occurs when some elephants in a population migrate into another area and join another population?
gene flow
genetic drift
microevolution
speciation
A river has cut a deep canyon that has separated a population of rodents into two groups. This separation is an example of what type of isolation?
geographic
temporal
behavioral
founder
The evolution of hummingbirds’ beaks
and plants with deep tubes in their flowers is an example of
coevolution
convergence
speciation
radiation
Evolution at the genetic level is called
microevolution
population genetics
allopatric speciation
genetic drift
The total genetic information available in a population is called the
gene pool
genetic equilibrium
'allele frequency
phenotype frequency
Reproductive isolation can result in
sympatric speciation
allopatric speciation
emigration
immigration
Genotypic variation in a population can increase through
recombination of genes by independent assortment
an increase of the quality and quantity of available food
maintenance of genetic equilibrium for many generations
prevention of immigration and emigration between populations
Genetic drift is
changes in allele frequency caused by random events
the movement of genes between populations
physical isolation of a population by geography
immigration and emigration among populations
What is a consequence of violating the Hardy-Weinberg genetic equilibrium assumptions?
evolution
reproductive isolation
mutation
sexual selection
The most common kind of selection, which results in the average form of a trait, is
stabilizing selection
sexual selection
direction selection
disruptive selection
The biological species concept is u�eful only for
organisms that reproduce sexually
organisms that reproduce asexually
extinct organisms
None of these
The morphological-species concept classifies organisms on the basis of their
structure and appearance
behavior
ability to reproduce
ecological relationships
Sexual selection is a form of
nonrandom mating
genetic drift
reproductive isolation
morphological speciation
Speciation often results from
disruptive selection
stabilizing selection
directional selection
sexual selection
Mice that have been separated into two populations by the construction of a new road through their range are considered
geographically isolated
prezygotically isolated
morphologically isolated
reproductively isolated
One source of genotypic variation that occurs within a single organism and that may be the result of environmental factors is
mutation
assortative mating
reproduction isolation
gene flow
For a certain population,
the actual frequencies
of a genotype did not
match the genotype frequencies predicted by
the Hardy-Weinberg equation. What can be said about the population?
The population is evolving.
Gene flow does not occur.
No mutations are occurring.
Allele frequencies are declining.
To be in Hardy-Weinberg equilibrium, a population must be
very large, have random mating, no gene flow, no mutations, no natural selection.
small, have nonrandom mating, no gene flow, many mutations, no natural selection.
very large, have random mating, high gene flow, many mutations, natural selection.
very small, have random mating, no gene flow, no mutations, no natural selection.
In a population of rattlesnakes that is evolving, which of the following statements is most likely true?
The rates of gene flow and mutation are high.
The population is in Hardy-Weinberg equilibrium.
Directional selection is probably not occurring.
Natural selection has no effect on this population.
When individuals from two populations of squirrels can no longer successfully mate with one another, the chance that speciation will occur
increases
stays the same
becomes zero
decreases
The wings of robins and the wings of dragonflies are examples of
convergent evolution
divergent adaptation
adaptive radiation
punctuated equilibrium
